Magnetic transmission or clutch



Dec. 1, 1942'. C, HELIN MAGNETIC TRANSMISSION oa CLUTCH www 2Sheets-Sheet l Filed Aug. 18, 1941 Dec. l, w42

C. J. HELEN MAGNETIC TRANSMISSION 0R CLUTCH 4 2 sheets-sheet 2 FiledAug. 18 1941 7 4 /0 4 W MW 2, l u m 3 Patented Dec. 1, 1942 UNITEDSTATES PATENT OFFICE 2,303,638 I Y MAGNETIC TRANSMISSION on CLUTCHCharles J. Helin, Burbank, Calif.

Application August 1s, 1941, serial No. 407,338

The primary object of my invention is the pro-r vision of a magnetictransmission or clutch inv which a variable speed driven member isefliciently impelled by a constant speed driving member.

A further object is the provision of a transmisn sion having no axialmovement of either the driving member or the driven member for effectingan operable connection between the said members.

Afurther object of the invention is the provision of a transmissionhaving no physical connection between the driving member and the drivenmember other than an electrically induced force.

A further object of the invention is to provide a transmission in whicha drivenk speed mayrbe made to approach a positive or constant speed inrelation to the driving speedwithout altering the transmission by simplyconnecting electrical controlling'eq'uipment.

A stur further object is to provide atraxismis'- sion which may be usedas a clutch in which the driven member willpick up with a gradual'oreven acceleration and assure a smoothly, non-jerking performance formaximum power transmittal, Malthough the current producing theinducedsforce 'may be increased rapidly tothe rated valueof speed.

Other objects and advantages of the invention Will more fully appear asthis specication proceeds and as is set forth in the appended claims.

I attain these objects by the device described in the accompanyingdrawings, in which:

Figure 1 is a vertical section of the invention as on line I-I of Fig. 2and Fig. 4.

Figure 2 is a section on line 2-2 of Fig. l.

Figure 3 is a section on line 3-3 of Fig. 2 and Fig. 4.

Figure 4 is a section on line 4-4 of Fig. 1.Y

Figure 5 is a section on line 5-5 of Fig. l.

Figure 6 is a section on line 6-6 of Fig. 3, and

Figure 7 is a diagram of one form of proposed electrical equipment forthe invention. l

Similar numerals and letters of reference refer to like parts throughoutthe several views, thus, the component parts of the invention comprise adriving member embodying a welded or otherwise formed frame Il) having acircular back or disk I I, a rim I2 and a hub I3 keyed to a drivingshaft I4^as at I5.

A dust cover I6 may be attached by screws I1 or otherwise to the frameI0 for protection of a pluwith suitable a. tightly wound clock spring,and is rotated in unison withthehub I3 by attachment screws 20 havingone end'jthreaded into said hub and extending radially through the coilI9.

Arched segments 2| within the rim I2 are compressed against the coil I9by the heads of the screws 20 to prevent loosening of the coil byvibration.

The coil I9 is milled at 22 to receive the wind- Y ings I8 as is shownbest in Fig. 6.

A positive slip ring 23 and a negative slip ring 24\are positioned aboutthe hub I3 to provide means forV electrical current connection to thetransmission. v

vA wire 25 represents the connection between the windings I8 and theslip ring 23.

lA driven member embodying a welded or otherwise formed frame 26, havinga back 21, a rim 28 and a hub 29 keyed to a driven shaft 30 as at 3i isprovided; a dust cover 32 for attachment to the `Aframe 26 by means ofscrews 33 may also be prorality of electrical windings I8 which formsepavided.

A continuousfsteel coil 34 is wound about the hub 30 and rotated withthe frame 26 by means I of one or more pins 35 connecting said coil withthe rim 28.

I' An inner rim 36 encompassing the coil 34 is disposed between saidcoil 34 and said rim 23. The rim 36 does not cover the full width of theperiph ery of the coil 34, but space is provided for the dispositionabout said coil of a plurality of arched copper segments 31.

The inner end of the hub 29 is reduced in diameter to provide space fora plurality of arched copper segments 38 forming a core within the coil34. The segmentends of the copper segments 31 and 33, are respectivelyslightly spaced, one from the other. The coil 34 is drilled radially toreceive a plurality ofcopper rods 39 adjacent the inner face of thedriven member.

The segments 31 and 38 are radially drilled to receive the outer andinner ends respectively of said copper rods 39 to which they aresoldered.

The coils I9 and 34 serve a purpose similar tothe laminations in aconventional induction motor and the windings I8 serve as the eld.

The operation of this invention resembles that of a conventionalinduction motor in which current is fed to the driving member (or field)only effecting a rotation of the driven member B if no current is fed tothe driving member A, but if a direct voltage is applied to the windingsI8 through the slip rings 23 and 24 a magnetic force will be applied tothe copper segments 31 and 38 and the copper rods 38 thereby causing thedriven member B to rotate in the same direction as the driving member A.

The speed of the driven member will vary more or less directly with theamount of current fed to the driving member until a maximum speed isreached. This maximum speed is determined by saturation point of theiron in the coils and the :timber of copper arched segments, the.greater the number of segments, the greater Will he he slip speedbetween the driving and the An member.

' lne speed ci the driven member will always be a small percentage lessthan that the driving member, the percentage varyingr th Consequently,with source of iec to the driving member and speed Een member.

ne speed of the driven member vill remain constant the load remainsconstant, but will have drooping speed load characteristics. If,however, a iorm of controlling equipment be connected to the slip rings23 and 24, such as the circuit shown in Fig. '7, the transmission may bemade positive Within the limits of said equipment.

Since the transmission will operate without any controlling equipment,and since a number of diiierent types of such equipment may readilyserve the identical purposes, the equipment diagrammed in Fig. '7 is notnecessarily a part of the invention, but is shown and described merelyto facilitate the explanation of the eiect of such an equipment inrelation to the transmission.

The equipment shown includes an A. C. generator irictionally driven fromthe frame 26 and adjustable as to speed by a movement toward or awayfrom the shaft 3d. Other components of the equipment connected to saidgenerator td. include a transformer 4i, an amplifier 2, a mixingtransformer 43, a detector 44, an interstage transformer 45, anamplifier 46, a coupling transformer 41, two grid controlled rectiiiersdil, and a filter 4S. Connected to the rectiers 6,8 is a variablevoltage power transiormer E8 for main eld current.

It also includes a doubler 5l, an interstage transformer 52, a rectierand doubler 53, and a power transformer 54, all connected to thetransformer 43. Wires 55 lead to the source of A. C. power, and wires 56provide an A. C. power connection to the slip rings 23 and 24.

The generator 40 controls the flow of current in the eld of the drivenmember by controlling the grids of the two mercury-vapor grid controlledrectiiers 48 which supply the primary field current.

The function of the controlling equipment is to cause the value of thecurrent flowing ln the field windings I8 to vary inversely with thespeed of the driven member B, i. e., if an increase of load were tooccur the dropping ofspeed of the driven member B would, by reason ofthe decrease in speed of the generator 4l, automatically cause anincrease in the eld current which would increase the magnetic forceaffecting the driven member, thereby pulling it back to its formerplace.

When the invention is used as a clutch, no controlling equipment isrequired.

.It may readily be produced from materials obtained in the open marketat no great cost, and, in operation, it provides a smoothly operatingmechanism possessing a cushioning action, rendering maximum performanceand practically trouble free.

I am aware that changes in construction of the device may from time totime readily suggest themselves, but within the scope herein set forth.Hence, l. do not limit my present invention to the exact description ofstructure herein disclosd, but what I do cla'im is: 2

l'. In a magnetic transmission, a rotary driving member including aframe, a coiled magnetic core fixed in said frame having radiallyextending recesses in one face thereof, a plurality of coil windingshaving portions fitted in said recesses, and other portionscircumscribing peripheral portions of said core which lie between saidrecesses, slip ring means for electrically' connecting said coilwindings with a source of electric current, a rotary driven member inaxially spaced rel-ation to the driving member including a frame,a'coiled magnetic core Xed in the frame of the driven member in opposedrelation to the core and coil windings of the driving member,circumferentially spaced copper segments at the center and periphery ofsaid driven member core, and copper rods connecting the peripheralsegments to the center segments and extending radially thru the core ofthe driven member.

2. In a magnetic transmission, a rotary driving member including aframe, a coiled magnetic core fixed in said frame having radiallyextending recesses in one face thereof, a plurality of coil windingshaving portions fitted in said recesses, and other portionscircuniscribing peripheral portions of said core which lie between saidrecesses, slip ring means for electrically connecting said-coil windingswith a source of electric current,/a rotary driven member in axiallyspaced relation to the driving member including a frame, a coiledmagnetic core xed in the frame of the driven member in opposed relationto the core and coil windings of the driving member, circumferentiallyspaced copper segments at the center and periphery of said driven membercore, copper rods connecting the peripheral segments to the centersegments and extending radially thru the core of the driven member, saidcoil windings forming separate poles, said driving member frameincluding a rim and a hub, arcuate segments engaged with the peripherycoiled core of the driving member and contacting said rim, and screwfastenings extending thru said rim., arcuate segments and core andthreaded into said hub, there being four of said coil windings incircumferentially spaced relation in a common plane' about the center ofthe core.^

CHARLES J. HELIN.

